package pony.myfilters;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;


// 該Filter是修改Tomcat的 webapps/examples/WEV-INF/classes/filter
public class SetCharacterEncodingFilter /* implements Filter */ {
    protected String encoding = null;
    protected FilterConfig filterConfig = null;
    protected boolean ignore = true;

    public void destroy() {
        this.encoding = null;
        this.filterConfig = null;

    }


    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
        	throws IOException, ServletException {
    	
        // Conditionally select and set the character encoding to be used
        if (ignore || (request.getCharacterEncoding() == null)) {
            String characterEncoding = selectEncoding(request);
            if (characterEncoding != null) {
              request.setCharacterEncoding(characterEncoding);
//              request.setCharacterEncoding("UTF-8");
            }
        }
        
        response.setContentType("text/html; charset=UTF-8");
        
        // Pass control on to the next filter
        chain.doFilter(request, response);

    }


    public void init(FilterConfig fConfig) throws ServletException {
        this.filterConfig = fConfig;
        this.encoding = fConfig.getInitParameter("encoding");
        String value = fConfig.getInitParameter("ignore");
        
        if (value == null)
            this.ignore = true;
        else if (value.equalsIgnoreCase("true"))
            this.ignore = true;
        else if (value.equalsIgnoreCase("yes"))
            this.ignore = true;
        else
            this.ignore = false;

    }
    
    protected String selectEncoding(ServletRequest request) {
        return (this.encoding);
    }

}
